John K.G. et al recommended clinical treatment toward Acanthamoeba keratitis using Diamidine and Biguanide which are the only two proofed Acanthamoeba cysticidal medication, while Metronidazole is effective in vivo but not in vitro. Topical steroid was considered rather controversial but important and beneficial. It was recommended to use a minimum of 2 weeks of Biguanide prior to the use of topical steroid for inflammation control. When Acanthamoeba keratitis was diagnosed early in the disease course, topical steroid can be spared for the immediate using Diamidine and Biguanide to kill pathogen. In a United Kingdom multicenter study of 218 patients, the average duration of medical therapy was 6 months (range, 0.5 to 29 months). In 2011, a little over half of respondents using corticosteroids in the treatment of Acanthamoeba keratitis. Surgical managements including epithelial debridement, cryotherapy and corneal graft surgery may itself be therapeutic if performed early and promote penetration. Therefore, when Acanthamoeba keratitis was suspected, a long-term and immediate medical treatment may be needed ,and the use of topical steroid toward Acanthamoeba keratitis is still worth investigating.